(written from a Production point of view)
Kathleen "Cathy" Demor is an actress who appeared as a regular background performer on Star Trek: Deep Space Nine and in at least one episode of Star Trek: Voyager. She received no on-screen credit for her appearances. Her costume as a female Klingon was sold off on the It's A Wrap! sale and auction on eBay.  Parts of this costume were reused and also worn by Spice Williams-Crosby, Thelma Lee, Marlene Sosebee, and Sandra Nelson. Another costume, worn by Demor in "Caretaker", was also sold off. 
Demor worked as a set costumer on the short film 9mm of Love in 2000. This film was produced, written, and directed by Robert Duncan McNeill and starred Ethan Phillips and TNG guest actress Liz Vassey. Among those involved in this production are second assistant director David Trotti, gun wrangler Alan Sims, make-up artists Suzanne Diaz and Scott Wheeler, background coordinator Pablo Soriano, stunt coordinators Dennis Madalone and Tom Morga, and stunt performers Patricia Tallman, Leslie Hoffman, Boni Yanagisawa, Chester E. Tripp III, John Lendale Bennett, Joey Sakata, Brian J. Williams, and Gary Ray Stearns.
Star Trek appearances
(This list is currently incomplete)
- DS9: as Starfleet officer